Framework for Two-Step Random Access Channel Procedure in Wireless Communication

Abstract

The present disclosure relates to a framework for a two-step random access channel process in wireless communication. In the first step of a two-step random access channel (RACH) process, a device may wirelessly transmit a first message on a physical RACH (PRACH) and a physical uplink shared channel (PUSCH). In the second step of the two-step RACH process, the device may receive a second message on a physical downlink shared channel (PDSCH) in response to successfully detecting the first message. When the first message is not successfully detected, the device may be instructed to fallback to a four-step RACH process. The device may be configured with one or more first message transmission opportunities (POs), one of which may include one or more PUSCH resource units (PRUs). Some of the communication parameters of the device may be configured to be common for each PO, while other communication parameters may be configured according to the PRU. New radio network temporary ID values may be defined for the first message and the second message, respectively.

Description

[0001] This application is a divisional application of the invention patent application with the application date of September 26, 2019, the application number of 201910918327.X, and the invention title of "Framework for Two-Step Random Access Channel Process in Wireless Communication". Technical Field

[0002] This application relates to wireless communication, and more particularly to a framework for a two-step random access channel (RACH) process in wireless communication such as 3GPP New Radio (NR) communication. Background Art

[0003] The use of wireless communication systems is growing rapidly. In recent years, wireless devices such as smart phones and tablet computers have become increasingly sophisticated. In addition to supporting telephone calls, many mobile devices (i.e., user equipment devices or UEs) now also provide access to the Internet, email, text messaging, and navigation using the Global Positioning System (GPS), and are capable of operating sophisticated applications that utilize these functions. Additionally, there are multiple different wireless communication technologies and standards. Some examples of wireless communication standards include GSM, UMTS (WCDMA, TDS-CDMA), LTE, LTE Advanced (LTE-A), HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), IEEE 802.11 (WLAN or Wi-Fi), IEEE 802.16 (WiMAX), BLUETOOTH TM etc. The next telecommunications standard beyond the current International Mobile Telecommunications Advanced (IMT-Advanced) standard is known as the 5th generation mobile network or 5th generation wireless system, called 3GPP NR (also known as 5G-NR of 5G New Radio, also simply referred to as NR). NR provides higher capacity for a higher density of mobile broadband users, while supporting device-to-device, ultra-reliable and massive machine communication, as well as lower latency and lower battery consumption compared to the current LTE standard.

[0004] When powered on, the UE typically starts searching for a network. There are the following possibilities: There are many networks or many frequencies from different network operators to which the UE can connect. Therefore, the UE needs to synchronize with each frequency and determine which of those frequencies the UE will connect to. The UE performs this function by going through an initial synchronization process. Once the UE has completed the synchronization process, the UE starts using the system information to establish wireless communication with the network (in the network). LTE system information includes the Master Information Block (MIB) and multiple System Information Blocks (SIBs). The MIB is broadcast on the Physical Broadcast Channel (PBCH), while the SIBs are sent on the Physical Downlink Shared Channel (PDSCH) via Radio Resource Control (RRC) messages (i.e., via RRC messages / signaling). The SI message can contain one or several SIBs.

[0005] Once the UE has achieved downlink synchronization, the MIB is the initial system information used by the UE and carries the most critical information required for the UE to obtain other information from the cell. The various different SIBs (e.g., LTE includes five different types of SIBs, namely SIB1 - SIB5) carry the remaining information required for the UE to perform wireless communication in the cell. LTE system information (SI) is transmitted in the Broadcast Control Logical Channel (BCCH). Generally speaking, BCCH messages are carried on the Downlink Shared Channel (DL - SCH) and are transmitted together with Downlink Control Information (DCI) messages that indicate the format and resource allocation of PDSCH transmission on the Physical Downlink Control Channel (PDCCH) on the Physical Downlink Shared Channel (PDSCH). The SI - RNTI (Radio Network Temporary Identity (RNTI) for system information) scrambles this DCI message. The exception is that the initial system information transmitted in the Master Information Block (MIB) as described above is carried on the BCH transport channel and transmitted on the PBCH.

[0006] Once the SIBs (at least SIB1) have been read, the UE performs a random access channel (RACH) procedure to initiate data transfer with the network. At this stage, there may be many other UEs performing similar procedures in the same area (e.g., in the same cell), and in this case, there is a possibility of conflicts among the requests from various other UEs. Such a RACH procedure is called a contention-based RACH procedure. However, the network can notify the UE to use a unique identity to prevent the UE's request from conflicting with requests from other UEs. Such a RACH procedure is called a contention-free RACH procedure or a non-contention-based RACH procedure. For an in-system handover request or a synchronization request for downlink data transfer (once synchronization is lost during downlink data transfer), a contention-free RACH procedure is performed. For moving from the radio resource control (RRC) idle state to the RRC connected state, a synchronization request for uplink data transfer (once synchronization is lost during uplink data transfer), or an RRC connection reestablishment request, a contention-based RACH procedure is performed. The overall function and structure of the MIB / SIB in NR are almost the same as those in LTE, but there are some differences.

[0007] The introduction of an increasing number of features and functions in wireless communication devices has also created a continuous need to improve wireless communication and wireless communication devices. Specifically, it is important to ensure the accuracy of the signals transmitted and received by user equipment (UE) devices (e.g., via wireless devices such as cellular phones, base stations, and relay stations used in wireless cellular communication). The UE (which can be a mobile phone or smartphone, portable gaming device, laptop computer, wearable device, PDA, tablet computer, portable Internet device, music player, data storage device, or other handheld device, etc.) is typically powered by a portable power source (e.g., a battery) and may have multiple radio interfaces that are capable of supporting multiple radio access technologies (RATs) defined by various wireless communication standards (LTE, LTE-A, NR, Wi-Fi, BLUETOOTH TM etc.). Currently, efforts are not only being made to reduce the power consumption required to perform wireless communication in order to improve the battery life of wireless devices, but also to effectively use wireless communication resources to improve system efficiency. One such effort focuses on reducing the number of communication steps required to perform the RACH procedure.

[0008] After comparing such prior art with the disclosed embodiments described herein, other corresponding problems related to the prior art will become apparent to those skilled in the art. Summary of the Invention

[0009] This document particularly presents embodiments of methods, procedures, etc. for supporting various devices, such as wireless communication devices, to perform a random access channel (RACH) procedure with a reduced number of steps (e.g., perform a two-step RACH procedure during 3GPP communication, such as during LTE and / or NR communication). This document further presents embodiments of a wireless communication system that includes wireless communication devices (UEs) and / or base stations and access points (APs) that communicate with each other within the wireless communication system.

[0010] In some embodiments, a device (e.g., a wireless communication device or UE) may communicate wirelessly over a network, and as part of the first step of a two-step RACH procedure, the device may transmit a physical random access channel (PRACH) and a first message (e.g., MsgA) on a physical uplink shared channel (PUSCH) to a base station. As part of the second step of the two-step RACH procedure, the UE may receive a second message (e.g., MsgB) on a physical downlink shared channel (PDSCH) from the base station in response to the base station successfully detecting the first message. The device may be configured with one or more opportunities to transmit the first message, where one opportunity includes one or more physical uplink shared channel resource units (PRUs). In some embodiments, one or more of the first set of communication parameters of the device (or associated with the device) may be configured to be common for each of the one or more opportunities, while one or more of the second set of communication parameters of the device (or associated with the device) may be configured according to the PRU. That is, different PRUs may be configured with the same parameters or they may be configured with different parameters.

[0011] The first set of parameters may include modulation and coding scheme (MCS) table parameters, periodicity parameters, bias parameters, demodulation reference signal (DMRS) configuration parameters, waveform parameters, power control parameters, and / or timer parameters. The second set of parameters may include MCS parameters, antenna port parameters, DMRS scrambling ID parameters, and / or frequency resource allocation and associated PRACH resource parameters.

[0012] In some embodiments, the first message may be associated with a specific value of a Radio Network Temporary Identifier (RNTI). The specific value may be determined based on the time and frequency resources associated with the PUSCH, the time and frequency resources associated with the PRACH, and / or the preamble index. Alternatively, the specific value may be determined by radio resource control. The specific value may be calculated according to a hash function of the first symbol index of the PUSCH resource, the slot index of the PUSCH within the transmission frame, the first resource block index of the PUSCH resource, and / or the preamble index used by the device to transmit the PRACH. A device in idle mode may use this specific value as the cell-RNTI value in accordance with the RACH procedure. Additionally, the device may use this specific value to determine whether there is a Phase Tracking Reference Signal (PT-RS) associated with the first message. The determination may include assuming that there is a PT-RS when the RNTI has this specific value, or assuming that there is no PT-RS when the RNTI has this specific value. Additionally, a second message may be used to indicate to the device the value of the Cell Radio Network Temporary Identifier (C-RNTI).

[0013] In some embodiments, when a conflict between the first message and the PRACH occurs in different Component Carriers (CCs), either the first message or the PRACH may be discarded by the UE. When a conflict between the first message and other uplink signals occurs in different CCs, the UE may discard the other uplink signals. When a conflict between the first message and the Physical Uplink Control Channel (PUCCH) occurs in the same CC, either the PUCCH or the first message may be discarded by the UE, or the uplink control information may be transmitted in the PUSCH. When a conflict between the first message and the Sounding Reference Signal (SRS) occurs in the same CC, either the first message or the SRS may be discarded by the UE.

[0014] In some embodiments, the device may receive an instruction from the base station to fallback to a 4-step RACH procedure in response to an unsuccessful detection of the first message. For example, when the first message (e.g., MsgA) and a downlink message (e.g., Msg3) that is part of a 4-step RACH procedure share the same control parameters and the PRACH is not correctly decoded, the base station may control the UE to fallback to a 4-step RACH.

[0015] In some embodiments, the second message may also be associated with a specific RNTI value. The specific value may be determined based on the time and frequency resources associated with the PUSCH, the time and frequency resources associated with the PRACH, the preamble index, and / or the uplink carrier type. Alternatively, the specific value may be determined by the RRC. The specific value may be calculated as a function of the first symbol index of the PUSCH occasion, the first slot index of the PUSCH occasion within a frame, the index of the PUSCH resources in the frequency domain, and / or the carrier type (e.g., normal uplink (NUL) carrier or supplementary uplink (SUL) carrier). The device may use the specific value to determine whether there is a phase-tracking reference signal (PT-RS) associated with the second message. The determination may include assuming that there is a PT-RS when the RNTI has the specific value, or assuming that there is no PT-RS when the RNTI has the specific value.

[0016] Note that the techniques described herein may be implemented in and / or used with multiple different types of devices, including but not limited to base stations, access points, cellular phones, portable media players, tablets, wearable devices, and various other computing devices.

[0017] This summary is intended to provide a brief overview of some of the subject matter described in this document. Accordingly, it should be understood that the above features are merely examples and should not be construed in any way as narrowing the scope or essence of the subject matter described herein. Other features, aspects, and advantages of the subject matter described herein will become apparent from the detailed description, the drawings, and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 An exemplary (and simplified) wireless communication system is shown in accordance with some embodiments;

[0019] Figure 2 An exemplary base station communicating with an exemplary wireless user equipment (UE) device is shown in accordance with some embodiments;

[0020] Figure 3 An exemplary block diagram of a UE is shown in accordance with some embodiments;

[0021] Figure 4 An exemplary block diagram of a base station is shown in accordance with some embodiments;

[0022] Figure 5 An exemplary simplified block diagram of an illustrative cellular communication circuit is shown in accordance with some embodiments;

[0023] Figure 6An exemplary signaling diagram is shown that illustrates a two-step random access channel (RACH) signaling process between an exemplary base station and a mobile device;

[0024] Figure 7 An exemplary code segment is shown listing possible radio resource control (RRC) parameters for a two-step RACH uplink message (MsgA) physical uplink shared channel (PUSCH) according to some embodiments; and

[0025] Figure 8 An exemplary signaling diagram is shown that illustrates a fallback from a two-step RACH process to a four-step RACH process between a base station and a mobile device according to some embodiments.

[0026] Although the features described herein are susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are described in detail herein. However, it should be understood that the drawings and the detailed description thereof are not intended to limit the present disclosure to the specific forms disclosed, but on the contrary, are intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter as defined by the claims. Detailed Description

[0027] Acronyms

[0028] Various acronyms are used throughout this application. The definitions of the most prominent acronyms that may appear throughout this application are as follows:

[0029] · AMR: Adaptive Multi-Rate

[0030] · AP: Access Point

[0031] · APN: Access Point Name

[0032] · APR: Application Processor

[0033] · BS: Base Station

[0034] · BSR: Buffer Status Report

[0035] · BSSID: Basic Service Set Identifier

[0036] · CBRS: Citizens Broadband Radio Service

[0037] · CBRSD: Citizens Broadband Radio Service Device

[0038] · CCA: Clear Channel Assessment

[0039] · CMR: Change Mode Request

[0040] · CS: Circuit Switched

[0041] DL: Downlink (from BS to UE)

[0042] DMRS: Demodulation Reference Signal

[0043] DSDS: Dual SIM Dual Standby

[0044] DYN: Dynamic

[0045] EDCF: Enhanced Distributed Coordination Function

[0046] FDD: Frequency Division Duplex

[0047] FO: First-order state

[0048] FT: frame type

[0049] GAA: General Authorization Access

[0050] GPRS: General Packet Radio Service

[0051] GSM: Global System for Mobile Communications

[0052] GTP: GPRS Tunneling Protocol

[0053] IMS: Internet Protocol Multimedia Subsystem

[0054] IP: Internet Protocol

[0055] IR: Initialization and refresh status

[0056] KPI: Key Performance Indicator

[0057] LAN: Local Area Network

[0058] LBT: Listen first, speak later

[0059] LQM: Link Quality Metric

[0060] LTE: Long Term Evolution

[0061] MNO: Mobile Network Operator

[0062] NB: Narrowband

[0063] NUL: Normal Uplink

[0064] OOS: Out of sync

[0065] PAL: Priority Access Licensee

[0066] PDCP: Packet Data Convergence Protocol

[0067] PDN: Packet Data Network

[0068] PDU: Protocol Data Unit

[0069] PGW: PDN Gateway

[0070] PLMN: Public Land Mobile Network

[0071] PRACH: Physical Random Access Channel

[0072] PSD: Power Spectral Density

[0073] PSS: Primary Synchronization Signal

[0074] PT: Payload Type

[0075] PUCCH: Physical Uplink Control Channel

[0076] PUSCH: Physical Uplink Shared Channel

[0077] QBSS: Basic Service Set with enhanced quality of service

[0078] QI: Quality Indicator

[0079] RAR: Random Access Channel Response

[0080] RAT: Radio Access Technology

[0081] RF: Radio Frequency

[0082] RACH: Random Access Channel

[0083] ROHC: Robust Header Compression

[0084] RRC: Radio Resource Control

[0085] RTP: Real-time Transport Protocol

[0086] RTT: Round Trip Time

[0087] RX: Receive

[0088] SAS: Spectrum Allocation Server

[0089] SID: System Identification Number

[0090] SIM: Subscriber Identity Module

[0091] SGW: Serving Gateway

[0092] SRS: Sounding Reference Signal

[0093] SSS: Secondary synchronization signal

[0094] SUL: Supplementary Uplink

[0095] · TBS: Transport Block Size

[0096] · TCP: Transmission Control Protocol

[0097] · TDD: Time Division Duplexing

[0098] · TX: Transmission / Tx

[0099] · UCI: Uplink Control Information

[0100] · UE: User Equipment

[0101] · UL: Uplink (from UE to BS)

[0102] · UMTS: Universal Mobile Telecommunications System

[0103] · USIM: UMTS Subscriber Identity Module

[0104] · WB: Wideband

[0105] · Wi-Fi: Wireless Local Area Network (WLAN) RAT based on Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards

[0106] · WLAN: Wireless Local Area Network

[0107] Terminology

[0108] The following is a glossary of terms that will appear in this application:

[0109] Memory medium - any of various types of memory devices or storage devices. The term "memory medium" is intended to include installation media such as CD-ROMs, floppy disks, or magnetic tape devices; computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory such as flash memory, magnetic media such as hard disk drives, or optical storage devices; registers, or other similar types of memory elements, etc. Memory medium may also include other types of memory or combinations thereof. In addition, the memory medium may be located in a first computer system that executes a program, or may be located in a different second computer system that is connected to the first computer system via a network such as the Internet. In the latter instance, the second computer system may provide program instructions to the first computer system for execution. The term "memory medium" may include two or more memory media that may reside at different locations in different computer systems connected, for example, via a network. The memory medium may store program instructions (e.g., embodied as a computer program) executable by one or more processors.

[0110] Carrier medium - The memory medium as described above, and physical transmission media such as buses, networks, and / or other physical transmission media that convey signals such as electrical, electromagnetic, or digital signals.

[0111] Programmable hardware elements - Include various hardware devices that include multiple programmable function blocks connected via programmable interconnects. Examples include FPGA (Field Programmable Gate Array), PLD (Programmable Logic Device), FPOA (Field Programmable Object Array), and CPLD (Complex PLD). The programmable function blocks can vary from fine-grained (combinational logic components or look-up tables) to coarse-grained (arithmetic logic units or processor cores). Programmable hardware elements can also be referred to as "configurable logic components".

[0112] Computer system (or computer) - Any of various types of computing or processing systems, including personal computer systems (PCs), mainframe computer systems, workstations, network appliances, Internet appliances, personal digital assistants (PDAs), television systems, grid computing systems, or other devices or combinations of devices. Generally, the term "computer system" can be broadly defined as any device (or combination of devices) that includes at least one processor that executes instructions from a memory medium.

[0113] User equipment (UE) (or "UE device") - Any of various types of computer system devices that perform wireless communication. Also referred to as wireless communication devices, many of which can be mobile and / or portable. Examples of UE devices include mobile phones or smartphones (e.g., iPhone TM , Android-based TM phones) and tablet computers such as iPad TM , Samsung Galaxy TM , etc., gaming devices (e.g., Sony PlayStation TM , Microsoft XBox TM , etc.), portable gaming devices (e.g., Nintendo DS TM , PlayStation Portable TM , Gameboy Advance TM , iPod TM ), laptop computers, wearable devices (e.g., Apple Watch TM , Google Glass TM)), PDAs, portable Internet devices, music players, data storage devices, or other handheld devices, etc. Various other types of devices that include Wi-Fi communication capabilities or both cellular and Wi-Fi communication capabilities and / or other wireless communication capabilities (e.g., via short-range radio access technology (SRAT) such as BLUETOOTH TM etc.) would fall into this category. Generally, the terms "UE" or "UE device" can be broadly defined to cover any electronic device, computing device, and / or telecommunications device (or combination of devices) that is capable of wireless communication and can also be portable / mobile.

[0114] Wireless device (or wireless communication device)—Any of various types of computer system devices that perform wireless communication using WLAN communication, SRAT communication, Wi-Fi communication, etc. As used herein, the term "wireless device" can refer to a UE device as defined above or a fixed device such as a fixed wireless client or a wireless base station. For example, a wireless device can be a wireless station of any type of 802.11 system, such as an access point (AP) or a client station (UE), or a wireless station of any type of cellular communication system that communicates according to a cellular radio access technology (e.g., LTE, CDMA, GSM), such as a base station or a cellular phone.

[0115] Communication device—Any of various types of computer systems or devices that perform communication, where the communication can be wired or wireless. A communication device can be portable (or mobile), or can be fixed or stationary at a certain location. A wireless device is an example of a communication device. A UE is another example of a communication device.

[0116] Base station (BS)—The term "base station" has the full scope of its ordinary meaning and includes at least a wireless communication station that is installed at a fixed location and is used for communication as part of a wireless telephone system or radio system.

[0117] Processor—Refers to various elements (e.g., circuits) or combinations of elements that are capable of performing functions in a device such as a user equipment device or a cellular network device. A processor can include, for example: a general-purpose processor and associated memory, parts or circuits of individual processor cores, entire processor cores or processing circuit cores, processing circuit arrays or processor arrays, circuits such as ASICs (application-specific integrated circuits), programmable hardware elements such as field-programmable gate arrays (FPGAs), and any various combinations of the above.

[0118] Channel - A medium for conveying information from a transmitter to a receiver. It should be noted that since the characteristics of the term "channel" can vary according to different wireless protocols, the term "channel" as used herein can be considered to be used in a manner that conforms to the standards of the type of device to which the term usage refers. In some standards, the channel width can be variable (e.g., depending on device capabilities, frequency band conditions, etc.). For example, LTE can support scalable channel bandwidths from 1.4 MHz to 20 MHz. In contrast, a WLAN channel can be 22 MHz wide, while a Bluetooth channel can be 1 MHz wide. Other protocols and standards can include different definitions of channels. In addition, some standards can define and use multiple types of channels, such as different channels for uplink or downlink and / or different channels for different purposes such as data, control information, etc.

[0119] Band (or frequency band) - The term "band" has the full range of its ordinary meaning and at least includes a segment of the spectrum (e.g., radio frequency spectrum) in which channels are used or reserved for the same purpose. In addition, "frequency band" is used to denote any interval in the frequency domain bounded by a lower frequency and a higher frequency. The term can refer to a radio frequency band or an interval of some other spectrum. A radio communication signal can occupy the frequency range that carries the signal (or in which the signal is located). Such a frequency range is also referred to as the bandwidth of the signal. Thus, bandwidth refers to the difference between the higher and lower frequencies in a continuous frequency band. A frequency band can represent a communication channel or it can be subdivided into multiple communication channels. The allocation of radio frequency ranges to different uses is a major function of radio spectrum allocation.

[0120] Wi-Fi - The term "Wi-Fi" has the full range of its ordinary meaning and at least includes a wireless communication network or RAT that is served by wireless LAN (WLAN) access points and provides connectivity to the Internet through these access points. Most modern Wi-Fi networks (or WLAN networks) are based on the IEEE 802.11 standard and are marketed under the name "Wi-Fi". Wi-Fi (WLAN) networks are different from cellular networks.

[0121] Automatically - refers to an action or operation performed by a computer system (e.g., software executed by a computer system) or a device (e.g., a circuit, a programmable hardware element, an ASIC, etc.) without the need for user input that directly specifies or performs the action or operation. Thus, the term "automatically" contrasts with an action or operation performed manually by a user, where the user provides input to directly perform the operation. An automatic process can be initiated by input provided by the user, but the subsequent actions that are "automatically" performed are not specified by the user, i.e., they are not performed "manually", where the user specifies each action to be performed. For example, a user filling out a spreadsheet by selecting each field and providing input to specify information (e.g., by typing information, selecting checkboxes, radio component selections, etc.) is a manual filling of the spreadsheet, even though the computer system must update the spreadsheet in response to the user's actions. The spreadsheet can be filled out automatically by a computer system, where the computer system (e.g., software executed on the computer system) analyzes the fields of the spreadsheet and fills out the spreadsheet without any user input specifying the answers to the fields. As indicated above, the user can initiate the automatic filling of the spreadsheet but does not participate in the actual filling of the spreadsheet (e.g., the user does not manually specify the answers to the fields but they are automatically completed). This specification provides various examples of operations that are automatically performed in response to actions taken by a user.

[0122] Approximately - means close to the correct or precise value. For example, approximately can refer to a value within 1% to 10% of the exact (or desired) value. However, it should be noted that the actual threshold (or tolerance) can depend on the application. For example, in some embodiments, "approximately" can mean within 0.1% of some specified or desired value, while in various other embodiments, depending on the expectations or requirements of a particular application, the threshold can be, for example, 2%, 3%, 5%, etc.

[0123] Concurrent - refers to the parallel execution or implementation, where tasks, processes, or programs are executed in at least a partially overlapping manner. For example, concurrency can be achieved using "strong" or strict parallelism, where tasks are (at least partially) executed in parallel on corresponding computing elements; or using "weak parallelism", where tasks are executed in an interleaved manner (e.g., by time multiplexing of execution threads).

[0124] Station (STA) - The term "station" in this document refers to any device that has the ability to communicate wirelessly (e.g., using the 802.11 protocol). A station can be a laptop computer, a desktop PC, a PDA, an access point, or a Wi-Fi phone or any type of device similar to a UE. A STA can be fixed, mobile, portable, or wearable. Generally speaking, in wireless networking terminology, the station (STA) broadly encompasses any device with wireless communication capabilities, and the terms station (STA), wireless client (UE), and node (BS) are thus often used interchangeably.

[0125] Configured to - Various components can be described as "configured to" perform one or more tasks. In such an environment, "configured to" is a broad statement generally indicating "having" the "structure" to perform one or more tasks during operation. Thus, even when the component is not currently performing a task, the component can be configured to perform that task (e.g., a set of electrical conductors can be configured to electrically connect a module to another module even when the two modules are not connected). In some environments, "configured to" can be a broad statement generally indicating "having" the "circuitry" to perform one or more tasks during operation. Thus, even when the component is not currently powered on, the component can be configured to perform a task. Generally, the circuitry forming the structure corresponding to "configured to" can include hardware circuitry.

[0126] For ease of description, various components can be described as performing one or more tasks. Such a description should be interpreted to include the phrase "configured to". A component described as configured to perform one or more tasks is expressly intended not to invoke the sixth paragraph of 35 U.S.C. § 112 for that component.

[0127] Figure 1 and Figure 2 - Exemplary communication system

[0128] Figure 1 FIG. shows an exemplary (and simplified) wireless communication system in accordance with some embodiments. Note that Figure 1 the system is only one example of possible systems, and embodiments can be implemented in any of a variety of systems as needed.

[0129] As shown, the exemplary wireless communication system includes base stations 102A through 102N, also collectively referred to as multiple base stations 102 or base station 102. As Figure 1 shown, base station 102A communicates with one or more user devices 106A through 106N via a transmission medium. Each user device can be referred to herein as a "user equipment" (UE) or UE device. Thus, user devices 106A through 106N are referred to as UEs or UE devices, and are also collectively referred to as multiple UEs 106 or UE as 106. Each of the UE devices is operable to perform a two-step random access channel (RACH) procedure in accordance with various embodiments disclosed herein.

[0130] Base station 102A can be a transceiver base station (BTS) or a cell site and may include hardware that enables wireless communication with UEs 106A through 106N. Base station 102A may also be equipped to communicate with network 100, such as the core network of a cellular service provider, a telecommunications network such as the public switched telephone network (PSTN) and / or the Internet, a neutral host, or various CBRS (Citizens Broadband Radio Service) deployments, and various possibilities. Thus, base station 102A can facilitate communication between user devices and / or between user devices and network 100. Specifically, cellular base station 102A can provide UEs 106 with various telecommunications capabilities such as voice, SMS, and / or data services. The communication area (or coverage area) of a base station may be referred to as a "cell". It should also be noted that a "cell" can also refer to the logical identity for a given coverage area at a given frequency. Generally, any independent cellular radio coverage area can be referred to as a "cell". In such a case, the base station can be located at the specific intersection of three cells. In such a uniform topology, the base station can serve three 120-degree beamwidth areas referred to as cells. Moreover, for carrier aggregation, small cells, relays, etc. can all represent cells. Thus, especially in carrier aggregation, there can be a primary cell and a secondary cell that serve at least partially overlapping coverage areas but on different respective frequencies. For example, a base station can serve any number of cells, and the cells served by the base station can be collocated or can be non-collocated (e.g., remote radio heads). Also as used herein, with respect to a UE, the base station can sometimes be considered to represent the network, taking into account the uplink and downlink communication of the UE. Thus, a UE that communicates with one or more base stations in the network can also be interpreted as a UE that communicates with the network, and can also be considered to be at least part of the UE communicating on or through the network.

[0131] The base station 102 and the user equipment may be configured to communicate via a transmission medium using any of various radio access technologies (RATs) (also referred to as wireless communication technologies) or telecommunication standards such as GSM, UMTS (WCDMA), LTE, LTE-Advanced (LTE-A), LAA / LTE-U, 5G-NR (abbreviated as NR), 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), Wi-Fi, WiMAX, etc. Note that if the base station 102 is implemented in the context of LTE, it may alternatively be referred to as an "eNodeB" or "eNB". Note that if the base station 102A is implemented in the context of 5G NR, it may alternatively be referred to as a "gNodeB" or "gNB". In some embodiments, the base station 102 may perform a two-step RACH process as described herein. Depending on the given application or specific considerations, for convenience, some different RATs may be grouped functionally according to an overall defined characteristic. For example, all cellular RATs may be uniformly considered to represent a first (form / type) RAT, while Wi-Fi communication may be considered to represent a second RAT. In other cases, the individual cellular RATs may be considered separately as different RATs. For example, when differentiating cellular communication from Wi-Fi communication, the "first RAT" may uniformly refer to all cellular RATs under consideration, while the "second RAT" may refer to Wi-Fi. Similarly, when applicable, different forms of Wi-Fi communication (e.g., over 2.4 GHz vs. over 5 GHz) may be considered to correspond to different RATs. Additionally, cellular communication performed according to a given RAT (e.g., LTE or NR) may be differentiated from each other based on the spectrum over which those communications are conducted. For example, LTE or NR communication may be performed on the primary licensed spectrum as well as on secondary spectrums such as the unlicensed spectrum and / or the spectrum allocated to Citizen Broadband Radio Service (CBRS). In general, the use of various terms and expressions will always be clearly indicated with respect to and within the context of the various application / embodiment environments under consideration.

[0132] As shown, base station 102A can also be configured to communicate with network 100 (e.g., among various possibilities, the core network of a cellular service provider, a telecommunications network such as the Public Switched Telephone Network (PSTN) and / or the Internet). Thus, base station 102A can facilitate communication between user devices and / or between user devices and network 100. Specifically, cellular base station 102A can provide UE 106 with various telecommunications capabilities such as voice, SMS, and / or data services. Thus, base station 102A and other similar base stations operating according to the same or different cellular communication standards (such as base stations 102B... 102N) can be provided as a network of cells that can provide continuous or nearly continuous overlapping services to UE106A - 106N and similar devices over a geographical area via one or more cellular communication standards.

[0133] Thus, although base station 102A can act as the "serving cell" of UE 106A - 106N as shown in Figure 1 , each of the UEs 106 is also capable of receiving signals (and potentially being within the communication range of these cells) from one or more other cells (which may be provided by base stations 102B - 102N and / or any other base stations) (which can be referred to as "neighboring cells"). Such cells may also be capable of facilitating communication between user devices and / or between user devices and network 100. Such cells can include "macro" cells, "micro" cells, "pico" cells, and / or any various other granularities of cells providing service area sizes. For example, Figure 1 base stations 102A - 102B shown in

[0134] can be macro cells, while base station 102N can be a micro cell. Other configurations are also possible.

[0135] As described above, the UE 106 is capable of communicating using multiple wireless communication standards. For example, the UE may be configured to communicate using any one or all of the 3GPP cellular communication standards (such as LTE or NR) or the 3GPP2 cellular communication standards (such as the cellular communication standards in the CDMA2000 series of cellular communication standards). Base stations 102 and other similar base stations operating according to the same or different cellular communication standards may thus be provided as one or more cell networks that can provide continuous or nearly continuous overlapping services to the UE 106 and similar devices over a wide geographical area via one or more cellular communication standards.

[0136] The UE 106 may also optionally be configured to use WLAN, BLUETOOTH TM , BLUETOOTH TM low power, one or more Global Navigation Satellite Systems (GNSS, such as GPS or GLONASS), one and / or more mobile television broadcast standards (such as ATSC-M / H or DVB-H), etc. for communication. Other combinations of wireless communication standards (including more than two wireless communication standards) are also possible. In addition, the UE 106 may also communicate with the network 100 through one or more base stations or through other devices, sites, or any appliances not explicitly shown but considered to be part of the network 100. Thus, communicating the UE 106 with the network can be interpreted as the UE 106 communicating with one or more network nodes that are considered to be part of the network and can interact with the UE 106 to communicate with the UE 106 and, in some cases, affect at least some communication parameters and / or the use of the communication resources of the UE 106.

[0137] In addition, as also Figure 1 shown, at least some UEs 106 (e.g., UEs 106D and 106E) may represent vehicles that communicate with each other and with the base station 102A via cellular communication such as 3GPP LTE and / or 5G-NR, for example. Additionally, the UE 106F may represent a pedestrian that is communicating and / or interacting with the vehicles represented by the UEs 106D and 106E in a similar manner. Other aspects of vehicles communicating in the network illustrated in Figure 1 are disclosed in the context of vehicle-to-everything (V2X) communication (such as the communication specified by 3GPP TS 22.185 V14.3.0, etc.).

[0138] Figure 2FIG. 0 shows an exemplary user equipment 106 (e.g., one of devices 106A through 106N) communicating with base station 102 and access point 112, according to some embodiments. The UE 106 can be a device with cellular communication capabilities and non-cellular communication capabilities (e.g., BLUETOOTH TM , Wi-Fi, etc.), such as a mobile phone, a handheld device, a computer, or a tablet, or almost any type of wireless device. The UE 106 can include a processor configured to execute program instructions stored in a memory. The UE 106 can perform any of the method embodiments described herein by executing such stored instructions. Alternatively or additionally, the UE 106 can include programmable hardware elements, such as an FPGA (field programmable gate array) configured to perform any of the method embodiments described herein or any part of any of the method embodiments described herein. The UE 106 can be configured to communicate using any of a plurality of wireless communication protocols. For example, the UE 106 can be configured to communicate using two or more of CDMA2000, LTE, LTE-A, NR, WLAN, or GNSS. Other combinations of wireless communication standards are possible.

[0139] The UE 106 can include one or more antennas for communicating using one or more wireless communication protocols according to one or more RAT standards (e.g., those mentioned above). In some embodiments, the UE 106 can share one or more portions of a receive chain and / or a transmit chain among multiple wireless communication standards. The shared radio components can include a single antenna, or can include multiple antennas for performing wireless communication (e.g., for MIMO). Alternatively, the UE 106 can include independent transmit chains and / or receive chains (e.g., including independent antennas and other radio components) for each wireless communication protocol it is configured to communicate with. As another alternative, the UE 106 can include one or more radio components or radio circuits shared among multiple wireless communication protocols, and one or more radio components uniquely used by a single wireless communication protocol. For example, the UE 106 can include shared radio components for communicating using either LTE or CDMA2000 1xRTT or NR, and independent radio components for communicating using each of Wi-Fi and BLUETOOTH TM . Other configurations are possible.

[0140] Figure 3 —Block diagram of an exemplary UE

[0141] Figure 3FIG. shows a block diagram of an exemplary UE 106 in accordance with some embodiments. As shown, the UE 106 may include a system-on-chip (SOC) 300, which may include portions for various purposes. For example, as shown, the SOC 300 may include a processor 302 that may execute program instructions for the UE 106, and a display circuit 304 that may perform graphics processing and provide a display signal to a display 360. The processor 302 may also be coupled to a memory management unit (MMU) 340 and / or other circuits or devices (such as the display circuit 304, the radio circuit 330, the connector I / F 320, and / or the display 360), and the MMU may be configured to receive addresses from the processor 302 and translate those addresses to locations in memory (e.g., memory 306, read-only memory (ROM) 350, NAND flash memory 310). The MMU 340 may be configured to perform memory protection and page table translation or setup. In some embodiments, the MMU 340 may be included as part of one or more processors 302.

[0142] As shown, the SOC 300 may be coupled to various other circuits of the UE 106. For example, the UE 106 may include various types of memory (e.g., including NAND flash 310), a connector interface 320 (e.g., for coupling to a computer system), a display 360, and wireless communication circuits (e.g., for LTE, LTE-A, NR, CDMA2000, BLUETOOTH TM , Wi-Fi, GPS, etc.). The UE device 106 may include at least one antenna (e.g., 335a), and may include multiple antennas (e.g., shown by antennas 335a and 335b) for performing wireless communication with a base station and / or other devices. Antennas 335a and 335b are shown by way of example, and the UE device 106 may include fewer or more antennas. Generally speaking, the one or more antennas are collectively referred to as one or more antennas 335. For example, the UE device 106 may use one or more antennas 335 to perform wireless communication via the radio circuit 330. As described above, in some embodiments, the UE may be configured to use multiple wireless communication standards for wireless communication.

[0143] As further described herein, the UE 106 (and / or the base station 102) may include hardware and software components for implementing at least a method for the UE 106 to perform the two-step RACH procedure detailed herein. One or more processors 302 of the UE device 106 may be configured to implement part or all of the methods described herein, such as by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). In other embodiments, one or more processors 302 may be configured as programmable hardware elements, such as an FPGA (Field Programmable Gate Array) or as an ASIC (Application Specific Integrated Circuit). Additionally, the processor 302 may be coupled to and / or interoperate with other components as shown in Figure 3 to perform the two-step RACH procedure according to the various embodiments disclosed herein. One or more processors 302 may also implement various other applications and / or end-user applications running on the UE 106.

[0144] In some embodiments, the radio circuitry 330 may include separate controllers dedicated to controlling communications for various respective RAT standards. For example, as shown in Figure 3 the radio circuitry 330 may include a Wi-Fi controller 356, a cellular controller (e.g., an LTE and / or NR controller) 352, and a BLUETOOTH TM controller 354, and in at least some embodiments, one or more or all of these controllers may be implemented as respective integrated circuits (simply referred to as ICs or chips), which communicate with each other and with the SOC 300 (more specifically with one or more processors 302). For example, the Wi-Fi controller 356 may communicate with the cellular controller 352 via a cell-ISM link or a WCI interface, and / or the BLUETOOTH TM controller 354 may communicate with the cellular controller 352 via a cell-ISM link or the like. Although three separate controllers are shown within the radio circuitry 330, other embodiments may have fewer or more similar controllers for various different RATs that may be implemented in the UE device 106. For example, at least one exemplary block diagram of some embodiments illustrating the cellular controller 352 is shown in Figure 5 and will be further described below.

[0145] Figure 4 — Block diagram of an exemplary base station

[0146] Figure 4 A block diagram of an exemplary base station 102 according to some embodiments is shown. Note that Figure 4The base station shown is only one example of a possible base station. As shown, base station 102 may include one or more processors 404 that may execute program instructions for base station 102. The one or more processors 404 may also be coupled to a memory management unit (MMU) 440 (which may be configured to receive addresses from the one or more processors 404 and translate those addresses into locations in memory, such as memory 460 and read-only memory (ROM) 450), or may be coupled to other circuits or devices.

[0147] Base station 102 may include at least one network port 470. The network port 470 may be configured to couple to a telephone network and provide access to a plurality of devices such as UE device 106 to the telephone network as described above in Figure 1 and Figure 2 . The network port 470 (or an additional network port) may be further configured or alternatively configured to couple to a cellular network, such as a core network of a cellular service provider. The core network may provide mobility-related services and / or other services to a plurality of devices such as UE device 106. In some cases, the network port 470 may be coupled to the telephone network via the core network, and / or the core network may provide the telephone network (e.g., in other UE devices served by the cellular service provider).

[0148] Base station 102 may include at least one antenna 434 and may include multiple antennas (e.g., as illustrated by antennas 434a and 434b) for wireless communication with mobile devices and / or other devices. Antennas 434a and 434b are shown as an example, and base station 102 may include fewer or more antennas. Generally, one or more antennas that may include antenna 434a and / or antenna 434b are collectively referred to as antenna 434. One or more antennas 434 may be configured to operate as a wireless transceiver and may be further configured to communicate with UE device 106 via radio circuitry 430. Antenna 434 may communicate with radio circuitry 430 via communication link 432. Communication link 432 may be a receive link, a transmit link, or both. Radio circuitry 430 may be designed to communicate via various radio telecommunications standards, which include but are not limited to LTE, LTE-A, 5G-NR (or simply NR), WCDMA, CDMA2000, etc. One or more processors 404 of base station 102 may be configured to implement part or all of the methods described herein, such as by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium) for causing base station 102 to communicate with a UE device that performs a two-step RACH process as disclosed herein. Alternatively, one or more processors 404 may be configured as a programmable hardware element such as an FPGA (field-programmable gate array) or as an ASIC (application-specific integrated circuit) or a combination thereof. In the case of some RATs (e.g., Wi-Fi), base station 102 may be designed as an access point (AP), in which case network port 470 may be implemented to provide access to a wide area network and / or one or more local area networks. For example, it may include at least one Ethernet port, and radio component 430 may be designed to communicate according to the Wi-Fi standard. Base station 102 may operate according to various methods and implementations disclosed herein for performing a two-step RACH process with a UE.

[0149] Figure 5 — Block diagram of an exemplary cellular communication circuit

[0150] Figure 5 An exemplary simplified block diagram of an exemplary cellular controller 352 is shown according to some embodiments. Note that Figure 5The block diagram of the cellular communication circuit is merely an example of one possible cellular communication circuit; other circuits, such as circuits that include or are coupled to sufficient antennas for different RATs to perform uplink activities using separate antennas, or circuits that include or are coupled to fewer antennas, such as circuits that can be shared among multiple RATs, are also possible. According to some embodiments, the cellular communication circuit 352 may be included in a communication device such as the communication device 106 described above. As described above, in addition to other devices, the communication device 106 may be a user equipment (UE) device, a mobile device or mobile station, a wireless device or wireless station, a desktop computer or computing device, a mobile computing device (e.g., a laptop computer, notebook or portable computing device), a tablet computer, and / or a combination of devices.

[0151] The cellular communication circuit 352 may be (e.g., communicatively; directly or indirectly) coupled to one or more antennas, such as antennas 335a - 335b and 336 as shown. In some embodiments, the cellular communication circuit 352 may include dedicated receive chains for multiple RATs (including and / or coupled to (e.g., communicatively; directly or indirectly) dedicated processors and / or radio components) (e.g., a first receive chain for LTE and a second receive chain for 5G NR). For example, as Figure 5 shown, the cellular communication circuit 352 may include a first modem 510 and a second modem 520. The first modem 510 may be configured for communication according to a first RAT (e.g., such as LTE or LTE-A), and the second modem 520 may be configured for communication according to a second RAT (e.g., such as 5G NR).

[0152] As shown, the first modem 510 may include one or more processors 512 and a memory 516 that communicates with the processors 512. The modem 510 may communicate with a radio frequency (RF) front end 530. The RF front end 530 may include circuitry for transmitting and receiving radio signals. For example, the RF front end 530 may include a receive circuit (RX) 532 and a transmit circuit (TX) 534. In some embodiments, the receive circuit 532 may communicate with a downlink (DL) front end 550, which may include circuitry for receiving radio signals via antenna 335a.

[0153] Similarly, the second modem 520 may include one or more processors 522 and a memory 526 communicatively coupled to the processors 522. The modem 520 may communicate with an RF front end 540. The RF front end 540 may include circuitry for transmitting and receiving radio signals. For example, the RF front end 540 may include a receive circuit 542 and a transmit circuit 544. In some embodiments, the receive circuit 542 may communicate with a DL front end 560, which may include circuitry for receiving radio signals via an antenna 335b.

[0154] In some embodiments, a switch 570 may couple the transmit circuit 534 to an uplink (UL) front end 572. Additionally, the switch 570 may couple the transmit circuit 544 to the UL front end 572. The UL front end 572 may include circuitry for transmitting radio signals via an antenna 336. Thus, when the cellular communication circuitry 352 receives an instruction to transmit according to a first RAT (e.g., supported by the first modem 510), the switch 570 may be switched to a first state that permits the first modem 510 to transmit signals according to the first RAT (e.g., via a transmit chain including the transmit circuit 534 and the UL front end 572). Similarly, when the cellular communication circuitry 352 receives an instruction to transmit according to a second RAT (e.g., supported by the second modem 520), the switch 570 may be switched to a second state that permits the second modem 520 to transmit signals according to the second RAT (e.g., via a transmit chain including the transmit circuit 544 and the UL front end 572).

[0155] As described herein, the first modem 510 and / or the second modem 520 may include hardware and software components for implementing any of the various features and techniques described herein. For example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium), the processors 512, 522 may be configured to implement some or all of the features described herein. Alternatively (or in addition), the processors 512, 522 may be configured as programmable hardware elements, such as field-programmable gate arrays (FPGAs) or as application-specific integrated circuits (ASICs). Alternatively (or in addition), in combination with one or more of the other components 530, 532, 534, 540, 542, 544, 550, 570, 572, 335, and 336, the processors 512, 522 may be configured to implement some or all of the features described herein.

[0156] In addition, as described herein, processors 512, 522 may include one or more processing elements. Accordingly, processors 512, 522 may include one or more integrated circuits (ICs) configured to perform the functions of processors 512, 522. Further, each integrated circuit may include circuits (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of processors 512, 522.

[0157] In some embodiments, the cellular communication circuit 352 may include only one transmit / receive chain. For example, the cellular communication circuit 352 may not include the modem 520, the RF front end 540, the DL front end 560, and / or the antenna 335b. As another example, the cellular communication circuit 352 may not include the modem 510, the RF front end 530, the DL front end 550, and / or the antenna 335a. In some embodiments, the cellular communication circuit 352 may also not include the switch 570, and the RF front end 530 or the RF front end 540 may communicate with the UL front end 572, e.g., directly.

[0158] RACH procedure

[0159] As previously mentioned, once the UE is powered on, the UE generally begins searching for a network, synchronizing with the detected frequencies, and determining which of those frequencies to connect to. Once the UE has completed the synchronization process, the UE uses the system information to perform a random access channel (RACH) procedure to initiate data transmission within (or with) the network. In today's systems, according to current 3GPP communication standards such as Rel-15 (version 15) of the 3GPP communication standard, the RACH procedure nominally involves a 4-step process. In contrast to the 4-step RACH procedure, a 2-step RACH procedure (or operation) is being proposed. Compared with the 4-step RACH procedure, the 2-step RACH procedure may help reduce latency.

[0160] Figure 6 An exemplary signaling diagram is shown that illustrates a two-step RACH signaling procedure between a base station 606 and a mobile device 106. As Figure 6 shown, in a first step 610, the UE 106 may transmit a physical random access channel (PRACH) and may also transmit a physical uplink shared channel (PUSCH) in a designated message referred to as "MsgA" to the base station (e.g., gNB) 606. In a second step 612, in response to successfully detecting the PRACH and MsgA in the first step 610, the base station 606 may transmit a response in a designated message referred to as "MsgB" to the UE 106. Reducing the number of steps in the RACH procedure from four (4) to two (2) raises new issues that need to be considered.

[0161] The first issue - control signaling for MsgA (PUSCH)

[0162] The MsgA PUSCH can be used by a UE in idle mode as well as a UE in connected mode. Thus, the transmission of the PUSCH can depend on a set of parameters that must be properly configured. Accordingly, the UE can be configured to have one or more MsgA PUSCH opportunities (POs), where one can include one or more PUSCH resource units (PRUs). In some embodiments, certain parameters can be configured commonly for each PO. Such parameters can include but are not limited to modulation and coding strategy (MCS) table parameters, periodicity parameters, offset parameters, demodulation reference signal (DMRS) configuration parameters, waveform parameters, power control parameters, and timer parameters. Additionally, certain parameters can be configured according to the PRU configuration, in which case these parameters can be configured commonly or differently according to the PRU as needed. Such parameters can include but are not limited to MCS parameters, antenna port parameters, DMRS scrambling ID parameters, frequency resource allocation, and associated PRACH resource parameters. In some embodiments, some of the above parameters can be configured in a PUSCH configuration or in other structures. Figure 7 An exemplary code segment according to some embodiments is shown, which lists possible radio resource control (RRC) parameters for a two-step RACH uplink message (e.g., for MsgA PUSCH). Figure 7 The parameters and code segment shown in can be used to define the RRC signaling for the two-step RACH procedure in 3GPP. For example, the code segment could be a proposed addition to section 6.2.3 of 3GPP technical specification 38.331.

[0163] Second issue - Radio network temporary identifier (RNTI) for MsgA PUSCH

[0164] For a four-step RACH, the RNTI of the first PUSCH message (e.g., Msg3) is configured by the network / base station (e.g., via the gNB) via a downlink message (e.g., Msg2). However, in the two-step RACH procedure, MsgA is transmitted before any downlink message. Thus, an RNTI must be defined for MsgA PUSCH, and retransmissions of MsgA PUSCH also need to be defined. To address the issues related to the RNTI of MsgA PUSCH, a new RNTI can be defined for MsgA PUSCH. The new RNTI can be referred to as MsgA-RNTI. At least three possible options for MsgA-RNTI can be considered.

[0165] The first option could be to determine the RNTI based on the time and frequency resources associated with the PUSCH, and / or by the time and frequency resources associated with the PRACH, and / or by the preamble index. In some embodiments, the RNTI can be calculated by the following function:

[0166] MsgA - RNTI = func(s, t, f, p),

[0167] where "func" represents a hash function, "s" represents the first symbol index of the PUSCH resource, "t" represents the slot index of the PUSCH resource in the frame, "f" refers to the first resource block index of the PUSCH resource, and "p" represents the preamble index used by the UE to transmit the PRACH. The second option may include configuring the RNTI via RRC, while the third option may include a combination of the first and second options, where the RNTI may be determined by RRC parameters and / or by the time and frequency resources associated with the PUSCH, and / or by the time and frequency resources associated with the PRACH, and / or by the preamble index. For the idle mode, the UE may use the MsgA - RNTI as the cell RNTI (C - RNTI) after the RACH procedure, or the C - RNTI may be indicated by the MsgB (or in the MsgB).

[0168] In addition, the dynamic presence of the phase - tracking reference signal (PT - RS) for the MsgA PUSCH may be predefined by considering a new RNTI such as MsgA - RNTI. According to the first option, if the RNTI (value) is equal to MsgA - RNTI, the UE may be configured to assume the absence of PT - RS transmission. For example, referring to 3GPP Technical Specification 38.214, v15.6.0, in section 6.2.3.2, when transform precoding is enabled and the UE is configured to have the higher - layer parameter transform precoding enabled in PTRS UplinkConfig, the UE may assume the absence of PT - RS when the RNTI is equal to MsgA - RNTI. According to the second option, if the RNTI (value) is equal to MsgA - RNTI, the UE may be configured to assume the presence of PT - RS. For example, referring to 3GPP Technical Specification 38.214, v15.6.0, section 6.2.3, when the UE is not configured to have the higher - layer parameter phase TrackingRS in DMRS UplinkConfig, the UE may assume the presence of PTRS when the RNTI is equal to MsgA RNTI. The third issue - UE behavior when the MsgA PUSCH conflicts with other signals

[0169] The operation of the UE can be configured to consider the possibility of conflict between MsgA PUSCH uplink transmission and other signals in the same component carrier (CC) or different CCs. In other words, when MsgA PUSCH and other signals are scheduled in the same symbol or time slot and transmitted in different CCs or the same CC, the UE may need to be aware of the possible conflict. If two different PUSCHs are transmitted in the same CC, the peak-to-average power ratio (PAPR) may increase, which may affect the uplink coverage. Therefore, in the same CC, it is preferable to keep the PAPR low, and to keep the PAPR low, it is preferable to avoid the simultaneous transmission of two different uplink channels. When the PUSCH and other signals are transmitted in different CCs and different beams, the UE may not be able to generate multiple beams simultaneously because the UE may only be able to generate a single beam in that time domain. Therefore, it is also preferable to avoid simultaneous multi-beam operation.

[0170] Therefore, in some embodiments, a set of rules can be defined to manage the operation of the UE when a conflict occurs between MsgA (PUSCH) transmission and other uplink signals of the UE. When a conflict between MsgA PUSCH and the PRACH occurs in different CCs, the UE may discard the MsgA PUSCH or the PRACH. When a conflict between MsgA PUSCH and other signals rather than the PRACH occurs in different CCs, the UE may discard the other signals. When a conflict between MsgA PUSCH and the physical uplink control channel (PUCCH) occurs in the same CC, the UE may discard the PUCCH, or alternatively, may discard the MsgA PUSCH, or in another alternative, the UCI carried by the physical uplink control channel (PUCCH) can be transmitted in the PUSCH. When a conflict between MsgA PUSCH and the sounding reference signal (SRS) occurs in the same CC, the UE may discard the SRS or the MsgA PUSCH.

[0171] The fourth issue - power control of MsgA PUSCH

[0172] It is necessary to determine / configure power control parameters and transmission power for the initial transmission and / or retransmission of MsgA PUSCH. For open-loop power control parameters, such as P0, α, etc., MsgA PUSCH can be configured with separate parameters via RRC. Alternatively, control parameters, such as power control parameters, can be common for MsgA PUSCH and Msg3 PUSCH, where the latter is part of the 4-step RACH procedure. For closed-loop power control parameters such as power ramping step size, etc., MsgA PUSCH can be configured with separate parameters via RRC, or alternatively, it can be configured with the same parameters as Msg3 PUSCH of the 4-step RACH procedure. If MsgA and Msg3 share the same power control parameters and during the process of successfully detecting the PRACH in the 2-step RACH procedure but not correctly decoding MsgA, the network (or base station, e.g., gNB) can control the UE to fallback to the 4-step RACH procedure. This is illustrated in Figure 8 as follows.

[0173] As Figure 8 shown, UE 106 can start the 2-step RACH procedure with the base station 606 by transmitting PRACH+MsgA PUSCH (1002). When the PRACH is successfully detected by the base station 606 while the MsgA PUSCH is not correctly detected, and the base station 606 can indicate to the UE 106 to fallback to the 4-step RACH procedure (1004) via a random access channel response (RAR). The UE can then transmit Msg3 to the base station 606 (1006), and the base station can communicate a contention resolution message to the UE 106 as a response (1008). In some embodiments, when the Msg3 transmission occurs during the 4-step RACH procedure executed as a fallback from the 2-step RACH procedure, additional power ramping can be imposed on the Msg3 transmission to improve the random access performance. In this case, the power ramping of the Msg3 transmission can be considered as:

[0174] f b,f,c (0,l)=ΔP rampup,b,f,c +δ msg2,b,f,c +ΔP rampupMsgA,b,f,c ,

[0175] where f b,f,c (0,l) is the closed-loop power control parameter, and ΔP rampup,b,f,c is configured for the MsgA power ramping step size. It should be noted for reference that examples of various power control parameters have been defined in 3GPP specifications, such as in section 7.1.1 of 3GPP TS 38.213.

[0176] The fifth issue - RNTI for MsgB transmission

[0177] For a 4-step RACH procedure, the RNTI is defined based on the RACH resource. In a 2-step RACH procedure, one RACH resource can be associated with multiple PUSCH resources. Therefore, different PUSCH resources can be associated with different MsgB transmissions. Since the procedure of the 2-step RACH procedure is different from that of the 4-step RACH procedure, in order to distinguish these two procedures, the RNTI for the MsgB transmission in the 2-step RACH procedure may need to be selected / determined to be different from the random access RNTI (RA-RNTI) for the Msg2 transmission in the 4-step RACH procedure. Therefore, it is necessary to define / determine the RNTI for the MsgB transmission, similar to determining / defining the RNTI for the MsgA PUSCH transmission.

[0178] According to the above, a new RNTI, such as MsgB-RNTI, can be defined for the MsgB transmission. The first option can determine the RNTI based on the time and frequency resources associated with the PUSCH, and / or the time and frequency resources associated with the PRACH, and / or the preamble index and / or the uplink carrier type. In some embodiments, the RNTI can be calculated as:

[0179] MsgB_RNTI = 1 + s_id + 14 * t_id + 14 * 80 * f_id + 14 * 80 * 8 * ul_carrier_id, where s_id indicates the first symbol index of the PUSCH resource, t_id indicates the first time slot index of the PUSCH resource within a frame, f_id refers to the index of the frequency domain resource associated with the PUSCH, and ul_carrier_id represents the carrier type, such as a normal uplink (NUL) carrier or a supplementary uplink (SUL) carrier. The second option can include configuring the RNTI by RRC, while the third option can include a combination of the first option and the second option, where the RNTI can be determined by RRC parameters and / or by the time and frequency resources associated with the PUSCH, and / or by the time and frequency resources associated with the PRACH, and / or by the preamble index.

[0180] In addition, when a new RNTI is defined for MsgB, the dynamic presence of PT-RS associated with MsgB transmission can also be pre-defined, such that the PT-RS can be present or absent. For example, according to the first option, if the RNTI (value) is equal to the MsgB-RNTI, the UE can be configured to assume the absence of PT-RS. For example, referring to 3GPP Technical Specification 38.214, v15.6.0, section 5.1.6.3, when the UE is configured with the higher layer parameter phase TrackingRS in DMRS DownlinkConfig and the RNTI is equal to the MsgB-RNTI, the UE can assume the absence of PT-RS. According to the second option, if the RNTI (value) is equal to the MsgB-RNTI, the UE can be configured to assume the presence of PT-RS. For example, again referring to 3GPP Technical Specification 38.214, v15.6.0, section 5.1.6.3, when the UE is configured with the higher layer parameter phase TrackingRS in DMRS DownlinkConfig, when the RNTI is equal to the MsgB-RNTI, the UE can assume the presence of PT-RS. It is well known that the use of personally identifiable information should follow privacy policies and practices that are recognized as meeting or exceeding industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of inadvertent or unauthorized access or use, and the nature of the authorized use should be clearly explained to the user.

[0181] Embodiments of the present invention can be implemented in any of a variety of forms. For example, in some embodiments, the present invention can be implemented as a computer-implemented method, a computer-readable memory medium, or a computer system. In other embodiments, the present invention can be implemented using one or more custom-designed hardware devices such as an ASIC. In other embodiments, the present invention can be implemented using one or more programmable hardware elements such as an FPGA.

[0182] In some embodiments, a non-transitory computer-readable memory medium (e.g., a non-transitory memory element) can be configured such that it stores program instructions and / or data, where if the program instructions are executed by a computer system, the computer system is caused to execute a method, such as any of the method embodiments described herein, or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein, or any combination of such subsets.

[0183] In some embodiments, a device (e.g., a UE) may be configured to include a processor (or a set of processors) and a memory medium (or memory elements), where the memory medium stores program instructions, where the processor is configured to read and execute the program instructions from the memory medium, where the program instructions are executable to implement any one of the various method embodiments described herein (or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein or any combination of such subsets). The device may be implemented in any of a variety of forms.

[0184] Although the above embodiments have been described in considerable detail, many variations and modifications will become apparent to those skilled in the art once the above disclosure is fully understood. The present invention is intended that the claims be construed to cover all such variations and modifications.

Claims

1. A method for performing wireless communication, the method comprising: Receiving, at a base station, from a device: Information on a Physical Random Access Channel (PRACH); And A first message on a Physical Uplink Shared Channel (PUSCH), wherein the first message is associated with a first Radio Network Temporary Identifier (RNTI) determined based on at least one or more resource parameters of the PRACH, and wherein there is no Phase Tracking Reference Signal (PT-RS) for the first message on the PUSCH according to the first RNTI; and Sending, by the base station, to the device any one of the following: A second message on a Physical Downlink Shared Channel (PDSCH) if the first message is successfully decoded, wherein the second message is associated with a second RNTI different from the first RNTI, and wherein there is no PT-RS for the second message on the PDSCH according to the second RNTI; or A Random Access Channel (RACH) fallback indication.

2. The method according to claim 1, wherein the base station has one or more opportunities to receive the first message, and one of the one or more opportunities includes one or more Physical Uplink Shared Channel Resource Units (PRUs).

3. The method according to claim 2, wherein one or more of a set of communication parameters are common to each of the one or more opportunities.

4. The method according to claim 3, wherein: The set of communication parameters includes one or more of the following: Modulation and Coding Scheme (MCS) table parameters; Periodicity parameters; Bias parameters; Demodulation Reference Signal (DMRS) configuration parameters; Waveform parameters; Power control parameters; or Timer parameters.

5. The method according to claim 2, wherein, One or more of the set of communication parameters are different for each PRU.

6. The method according to claim 5, wherein, The set of communication parameters includes one or more of the following: MCS parameters; Antenna port parameters; DMRS scrambling ID parameters; or Frequency resource allocation and associated PRACH resource parameters.

7. The method according to claim 1, wherein the first RNTI is determined based on one or more of the following: Time and frequency resources associated with the PUSCH; Time and frequency resources associated with the PRACH; or Preamble index; and wherein the second RNTI is determined based on one or more of the following: The time and frequency resources associated with the PUSCH; The time and frequency resources associated with the PRACH; The preamble index; or Uplink carrier type.

8. The method according to claim 1, wherein one or more of the first RNTI and the second RNTI are determined by Radio Resource Control (RRC).

9. The method according to claim 1, wherein the first RNTI is calculated according to a hash function of the following: A first symbol index of resources associated with the PUSCH; A slot index of the PUSCH within a transmission frame; A first resource block index of the resources associated with the PUSCH; and The preamble index used by the device to transmit the information on the PRACH.

10. The method according to claim 1, wherein the second RNTI is calculated according to a function of the following: a first symbol index of the timing of the PUSCH; a first time slot index of the timing of the PUSCH within a frame; an index of a frequency domain resource associated with the PUSCH; or a carrier type.

11. The method according to claim 1, wherein for the device in an idle mode after a RACH procedure of the device, the first RNTI is a cell RNTI.

12. The method according to claim 1, wherein a second message indicates the cell RNTI to the device.

13. The method according to claim 1, further comprising: when a conflict between the first message and the information occurs in different component carriers, discarding one of the first message or the information.

14. The method according to claim 1, further comprising: when a conflict between the first message and one or more uplink signals occurs in different component carriers, discarding the one or more uplink signals.

15. The method according to claim 1, further comprising: when a conflict between the first message and a physical uplink control channel PUCCH occurs in the same component carrier, performing one of the following: discarding the PUCCH; discarding the first message; or transmitting uplink control information in the PUSCH.

16. The method according to claim 1, further comprising: when a conflict between the first message and a sounding reference signal SRS occurs in the same component carrier, discarding one of the first message or the SRS.

17. The method according to claim 1, wherein the first message and a downlink message sent by a base station according to the RACH backoff indication share the same control parameters.

18. An electronic device, comprising: a processor configured to execute the method according to any one of claims 1-17.

19. An electronic device, comprising: a radio circuit configured to facilitate wireless communication of the device via a wireless network; and a processor communicatively coupled to the radio circuit and configured to execute the method according to any one of claims 1-17.

20. A non-transitory memory element storing instructions executable by a processor to execute the method according to any one of claims 1-17.

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